Wave-induced steady forces and yaw moment of a ship advancing in oblique waves
Wave-induced steady forces and yaw moment of a ship advancing in oblique waves
复制标题
DOI：
10.1007/s00773-017-0510-6
复制
发表时间：
2018-12
影响因子：
2.6
通讯作者：
Ardhana Wicaksono;M. Kashiwagi
中科院分区：
文献类型：
--
作者：
Ardhana Wicaksono;M. Kashiwagi
基于动量守恒和能量守恒原理，采用远场法研究了前向航速下波浪引起的附加阻力、稳态横荡力和稳态横摆力矩，这些附加阻力、横荡力和横摆力矩均为入射波幅的二阶。采用增强统一理论（EUT）和新条带法（NSM）对远场法中的重要输入数据--船舶扰动波的Kochin函数进行了计算，分析了船首波绕射、三维和前进速度对二阶定常力和力矩最终结果的影响。特别注意的是精细积分法，以确保收敛在半无限积分的计算公式，不引入人工衰减因子，不像传统的条带理论方法。通过与散货船模型在规则斜波和自由运动条件下的试验比较，验证了本文计算方法的正确性。计算结果与实测结果吻合较好，在较宽的波频范围内，对于船舶运动的所有模态以及定常力和偏航力矩，EUT的性能优于NSM。
Wave-induced added resistance, steady sway force, and steady yaw moment, which are of second order in the incident-wave amplitude, are studied for the forward-speed case using the far-field method based on the principles of momentum and energy conservation. The Kochin functions representing ship-disturbance waves, important input data in the far-field method, are evaluated by means of both enhanced unified theory (EUT) and new strip method (NSM) to see the difference due to bow wave diffraction, 3D and forward-speed effects in the final results of second-order steady forces and moment. Special attention is paid on the precise integration method to ensure convergence in semi-infinite integrals in the calculation formulae, introducing no artificial decaying factor unlike conventional strip-theory methods. Validation of the present calculation method is made through comparison with the experiment conducted with a bulk-carrier model advancing in regular oblique waves and motion-free condition. Good agreement between computed and measured results and also superiority of EUT to NSM are confirmed for all modes of ship motion and the steady forces and yaw moment in a wide range of wave frequency.